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Clinical relevance: Central retinal artery occlusion (CRAO) is an ophthalmic emergency with a poor prognosis. Several initial CRAO presentation factors can influence the final visual outcome. Fluorescein angiography filling of retinal vessels in CRAO has not been studied in great detail. Background: The aim of this paper is to study the aberrant filling of the retinal vessels on fluorescein angiography in patients with CRAO and understand its clinical relevance. Methods: Cases of CRAO diagnosed between June 2017 and May 2022 and who had undergone a fundus fluorescein angiography were included. Comparisons were made between the cases with and without aberrant filling of the retinal vessel. Results: Twenty-two eyes of 22 patients (14 males and 8 females) with CRAO underwent fluorescein angiography. Ages of the patients ranged from 18 to 73 years, while time interval between development of acute onset vision problems and presentation to the retinal clinic ranged from a minimum of 1 day to a maximum of 30 days. Snellen visual acuity at presentation ranged from perception of light (PL +) to 6/6. On fluorescein angiography, aberrant flow of the fluorescein dye into the retinal vein was observed in four of the 22 (18%) eyes with CRAO. All these cases showed a patient's temporal cilioretinal artery. The cases with aberrant filling of the retinal vessels showed a better presenting visual acuity (6/6–6/60), lesser severity of inner retinal damage and a better final visual acuity (6/6–6/60) compared to CRAO cases without aberrant filling. Conclusion: Aberrant filling of the retinal vein can be seen on fluorescein angiography in eyes with CRAO and a patent temporal cilioretinal artery. Such eyes with aberrant retinal vessel filling have a better visual prognosis. [ABSTRACT FROM AUTHOR]

Introduction: To investigate the impact of posterior vitreous detachment (PVD) on the risk of developing neovascular glaucoma (NVG) in eyes with occlusions of the retinal artery (RAO) or retinal vein (RVO). Methods: Single-center retrospective case-control study of adults with a history of RVO/RAO. Cases (N = 101) who developed NVG were age and sex matched 1:2 to controls who did not develop NVG (N = 202). Multivariable logistic regression was used to estimate the association between history of PVD and risk of NVG while controlling for other related demographic or clinical factors. Results: In initial bivariate analyses, there was no difference in risk of NVG based on eye, lens status, hypertension, history of panretinal photocoagulation (PRP), or retinal surgery (all p > 0.10), a borderline difference based on diabetic retinopathy (DR) (p = 0.06) and prior anti-vascular endothelial growth factor (anti-VEGF) treatment (p = 0.08), and a significant difference based on race/ethnicity, type of vascular event, and PVD status (all p < 0.05). In the final multivariable model, patients without PVD were significantly more likely to develop NVG (OR = 3.07, p = 0.0001) independent of the other covariates. Risk of NVG was greater in those with DR (OR = 1.98, p = 0.0440) and in those with central RVO vs. branch RVO/hemiretinal RVO (OR = 5.77, p < 0.0001). Non-White/Non-Hispanics (OR = 2.56, p = 0.0051) and Hispanics (OR = 3.65, p = 0.0288) were more likely than White patients to develop NVG. Conclusions: Progression to NVG after retinal vascular occlusion is more likely in Non-White/Hispanic patients, those with concomitant DR, and those with CRVO/CRAO. The absence of PVD increases the risk for NVG. Further studies are necessary to understand this relationship. [ABSTRACT FROM AUTHOR]

Retinal vein occlusion (RVO) and cerebrovascular disease share common risk factors and may be independently associated; however, the strength and nature of this association remain unclear. We conducted a systematic review and meta-analysis, informed by studies from PubMed, Scopus, EMBASE, Web of Science, and Google Scholar until January 6, 2024, aimed to clarify this relationship. Eligible studies included cohorts observing stroke incidence in RVO patients for over a year. Pooled effect estimates were calculated using random-effects models, with subgroup analyses evaluating associations between RVO types (central and branch) and stroke subtypes (ischemic and hemorrhagic). Ten cohort studies with a total of 428,650 participants (86,299 RVO patients) were included. Compared to controls, RVO patients exhibited a significantly increased risk of stroke (pooled risk ratio [RR]=1.38, 95 % confidence interval (95 %CI)=1.34–1.41). Subgroup analyses indicated elevated risk for both ischemic (RR=1.37, 95 %CI=1.32–1.42) and hemorrhagic (RR=1.55, 95 %CI=1.08–2.22) strokes in RVO patients. Additionally, both central (RR=1.50, 95 %CI=1.27–1.78) and branch (RR=1.41, 95 %CI=1.32–1.50) RVO were associated with stroke risk. Sensitivity analyses confirmed consistent results across various criteria, and funnel plots indicated no publication bias. RVO significantly increases the risk of both ischemic and hemorrhagic stroke, regardless of RVO type, suggesting a strong independent association between these conditions. [ABSTRACT FROM AUTHOR]

A 51‐year‐old male underwent vitrectomy with retrobulbar anesthesia for retinal detachment. Post surgery, he experienced systemic hypotension which normalized after 3 h. The day after, he complained of a central scotoma in the operated eye. Intraocular pressure was normal, but fundus examination revealed hemorrhages and whitening along the papillomacular bundle and macula, with additional whitening in the upper midperipheral region. Multimodal imaging confirmed branch retinal vein, artery, and cilioretinal artery occlusion. Further examination revealed mild‐to‐moderate obstructive sleep apnea syndrome. Vascular occlusions are potential complications of vitreoretinal surgery, warranting thorough preoperative assessment for underlying risk factors, even if causative mechanism is still unknown. [ABSTRACT FROM AUTHOR]

Purpose: To present a novel optical model explaining why the vast majority of patients with Asteroid Hyalosis (AH) do not perceive any floaters. This changes our understanding of floater perception and undermines the operation mode of YAG laser vitreolysis. Methods: Relying on a previously published model of floater perception based on astronomical equations of a solar eclipse, and on ultrasound images of the vitreous in three eyes with AH, we explain why such patients do not perceive floaters in spite of opaque bodies filling their entire vitreous, to the point of, in severe cases of AH, obscuring the fundus view during ophthalmoscopy. Main outcome measures: Developing an optical model of light rays that can quantify the maximal distance upon which a vitreous floater or opacity will cast a shadow on the retina. Results: Calculations using the proposed model demonstrated that with a 3 mm pupil, for a floater located between 1.5 mm and 2 mm from the retina, its shortest diameter must be > 215 microns and > 286 microns, respectively, to be perceived. Since AH floaters, based on ultrasound imaging, do not exist in the most peripheral 1.5 mm of the vitreous, it becomes understandable why these patients are asymptomatic. Conclusions: Based on the proposed model and our findings, we deduced that even large, degenerative floaters whose width is usually narrower than a large retinal vein (125 microns), must be located very close to the retina and hence are not the floaters that are aimed at when performing YAG laser vitreolysis. We speculate that in successful cases, YAG vitreolysis works by a different mechanism, most likely a shock wave that displaces floaters further away from the retina. Hence, vitreolysis might not necessarily require the laser be aimed at the floaters, as symptomatic floaters may be located in the outer 1.5–2.0 mm of the vitreous body, a very risky zone for YAG laser shots. [ABSTRACT FROM AUTHOR]

Background: Chronic myeloid leukemia (CML) can manifest ocular complications stemming from hematologic irregularities or direct infiltration of neoplastic cells. This article details the case of a patient with newly diagnosed CML exhibiting elevated platelet counts (PLT) who developed panuveitis accompanied by retinal vascular occlusion. Case presentation: A 52-year-old woman experienced a notable decline in vision in her left eye over a 2-week period. Classical anterior uveitis, vitreous cavity opacity, optic nerve edema, and retinal vascular obstruction were observed. The right eye exhibited papilledema and retinal vein tortuosity. Despite admission, the condition of both eyes deteriorated, accompanied by a continuous increase in PLT. She was diagnosed with CML based on bone marrow biopsy and chromosomal examination. Following platelet apheresis therapy and chemotherapy, the condition of her right eye significantly improved, but the left eye's condition remained irreversible. Conclusions: This is a rare case of newly diagnosed CML presenting with diverse ocular manifestations in both eyes. The disparate outcomes in eyes with varying lesion stages underscore the importance of prompt diagnosis. [ABSTRACT FROM AUTHOR]

Aims Methods and results Conclusion To investigate the changes in retinal microvasculature by contemporary imaging techniques during episodes of acute decompensated heart failure (ADHF) and following recompensation compared to age‐matched controls without known cardiac or retinal disease.Adult patients hospitalized with a primary diagnosis of ADHF, regardless of left ventricular ejection fraction (LVEF) and treated with a minimum dose of 40 mg of intravenous furosemide or equivalent were included. Transthoracic echocardiography was conducted in all patients. Eye examinations were performed out within the initial 24 h after admission and after recompensation before discharge. All eyes underwent a general examination, including a best corrected visual acuity test, dilated fundoscopy, spectral‐domain optical coherence tomography (OCT) as well as OCT angiography (OCT‐A). In addition, 40 participants without documented cardiac or retinal diseases served as controls. Forty patients with ADHF (mean age 78.9 ± 8.8 years; 32% female) with a mean LVEF of 43 ± 12.8% were included. All patients were treated with intravenous diuretics for a median of 4.3 ± 2.8 days. There was a significant reduction in N‐terminal pro‐B‐type natriuretic peptide from baseline up to discharge (10 396 [interquartile range 6410] vs. 6380 [interquartile range 3933] pg/ml, p ≤ 0.001) and inferior vena cava diameters (2.13 ± 0.4 vs. 1.63 ± 0.3 cm, p = 0.003). Compared to the control group, patients with ADHF showed on admission impaired visual acuity (0.15 ± 0.1 vs. 0.35 ± 0.1 logMAR, p < 0.001), reduced macular vessel density (18.0 ± 1.9 vs. 14.3 ± 3.6 mm/mm2, p < 0.001) and perfusion density (42.6 ± 3.2 vs. 35.2 ± 9.7%, p < 0.001). After recompensation, the mean overall vessel density and mean overall perfusion density were markedly increased at discharge (14.3 ± 3.6 vs. 19.7 ± 2.6 mm/mm2, p = 0.001, and 35.2 ± 9.7 vs. 39.2 ± 6.5%, p = 0.005, respectively). The mean diameter of the superior temporal retinal vein at admission was significantly larger compared to the control group (136 ± 19 vs. 124 ± 22 μm, p = 0.008) and decreased significantly to 122 ± 15 μm at discharge (p < 0.001).This analysis revealed a remarkable reversible change in retinal microvasculature after ADHF. This could provide a valuable evidence for use of OCT‐A in the assessment of overall microperfusion and haemodynamic status in patients with acute heart failure. [ABSTRACT FROM AUTHOR]

Central retinal vein occlusion typically manifests in older individuals with underlying systemic pathology, leading to a spectrum of symptoms ranging from blurred vision to complete vision loss. While odontogenic infections are recognized for causing complications affecting the eye and vision, their potential role as an etiological factor in cases of sudden vision impairment merits consideration. This article presents a case involving central retinal vein thrombosis, wherein resolution was achieved through a combination of ophthalmic therapy and the surgical removal of a concurrently existing large inflamed odontogenic cyst located in the ipsilateral hemimaxilla. This case underscores the importance of recognizing odontogenic factors in the assessment of sudden vision impairment and the efficacy of a multidisciplinary therapeutic approach. [ABSTRACT FROM AUTHOR]

Automatic segmentation of the fundus retinal vessels and accurate classification of the arterial and venous vessels play an important role in clinical diagnosis. This article proposes a fundus retinal vascular segmentation and arteriovenous classification network that combines the adversarial training and attention mechanism to address the issues of fundus retinal arteriovenous classification error and ambiguous segmentation of fine blood vessels. It consists of three core components: discriminator, generator, and segmenter. In order to address the domain shift issue, U‐Net is employed as a discriminator, and data samples for arterial and venous vessels are generated with a generator using an unsupervised domain adaption (UDA) approach. The classification of retinal arterial and venous vessels (A/V) as well as the segmentation of fine vessels is improved by adding a self‐attention mechanism to improve attention to vessel edge features and the terminal fine vessels. Non‐strided convolution and non‐pooled downsampling methods are also used to avoid losing fine‐grained information and learning less effective feature representations. The performance of multi‐class blood vessel segmentation is as follows, per test results on the DRIVE dataset: F1‐score (F1) has a value of 0.7496 and an accuracy of 0.9820. The accuracy of A/V categorization has increased by 1.35% when compared to AU‐Net. The outcomes demonstrate that by enhancing the baseline U‐Net, the strategy we suggested enhances the automated classification and segmentation of blood vessels. [ABSTRACT FROM AUTHOR]

Retinal vein occlusion (RVO) is a significant cause of vision loss, characterized by the occlusion of retinal veins, leading to conditions such as central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Macular edema (ME), a prevalent consequence of RVO, is the primary cause of vision impairment in affected patients. Anti-VEGF agents have become the standard treatment, showing efficacy in improving visual acuity (VA) and reducing ME. However, a subset of patients exhibit a suboptimal response to anti-VEGF therapy, necessitating alternative treatments. Corticosteroids, which address inflammatory pathways implicated in ME, have shown promise, particularly in cases resistant to anti-VEGF. This review aims to identify biomarkers that predict treatment response to corticosteroids in RVO-associated ME, utilizing multimodal imaging and cytokine assessments. Baseline imaging, including SD-OCT and OCT-A, is essential for evaluating biomarkers like hyperreflective foci (HRF), serous retinal detachment (SRF), and central retinal thickness (CRT). Elevated cytokine levels, such as IL-6 and MCP-1, correlate with ME severity and poor anti-VEGF response. Early identification of these biomarkers can guide timely transitions to corticosteroid therapy, potentially enhancing treatment outcomes. The practical conclusion of this review is that integrating biomarker assessment into clinical practice enables personalized treatment decisions, allowing for earlier and more effective management of RVO-associated ME by transitioning patients to corticosteroid therapy when anti-VEGF agents are insufficient. Advanced diagnostics and machine learning may further refine personalized treatment strategies, improving the management of RVO-associated ME. [ABSTRACT FROM AUTHOR]

Purpose: This study is to investigate the increase in retinal venous pressure (RVP) induced by a stepwise increase in airway pressure (AirP) using the new IOPstim method, which is designed to artificially increase the intraocular pressure (IOP) and thus to stimulate vascular pulsation. Methods: Twenty-eight healthy subjects were examined in the left eye. The RVP was measured at baseline and at four different levels of AirP (10, 20, 30, and 40 mmHg) using the new IOPstim method: a half balloon of 8 mm diameter is inflated laterally to the cornea under observation of the central retinal vein. As soon as the vein pulsates at a certain AirP level, the IOP is measured with a commercially available tonometer, which then corresponds to the RVP. Results: Spontaneous venous pulsation was observed in all study participants. The mean RVP values at baseline and at the AirP levels of 10, 20, 30, and 40 mmHg were 17.6 ± 2.8 mmHg; 20.1 ± 3.0 mmHg; 22.1 ± 3.5 mmHg; 24.3 ± 3.7 mmHg, and 26.6 ± 4.2 mmHg, respectively. The mean RVP values of each AirP level were statistically significantly different from each other in pairwise comparison. In a linear mixed model, the effect of AirP on RVP was highly significant (p < 0.001). In the model, a 10-mmHg increase in AirP resulted in a linear increase in RVP of 2.2 mmHg. Conclusion: An increase in AirP was accompanied by a linear increase in RVP. The influence of AirP on RVP, and thus on retinal perfusion pressure during the Valsalva maneuver, is less than was assumed based on previous studies in which contact lens dynamometry was used. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To investigate the effects of topically applied 1% tropicamide, 2.5% phenylephrine and 1% cyclopentolate on retinal vessel calliper (VC) using optical coherence tomography (OCT). Methods: Patients who came to the ophthalmology clinic for routine examination and whose OCT films were taken before dilatation and after 30 min of last dilatation drop were included in the study. 90 ophthalmologically healthy subjects were divided into 3 groups of 30 subject each according to the application of the drops as follows: Tropicamide group (Group 1), Phenylephrine group (Group 2), Cyclopentolate group (Group 3). The right eyes of the subjects were dilated with drops and the left eyes were taken as the control group. VC of retinal artery and vein passing through an area one-half to one-disc diameter from the optic disc margin were measured from OCT films. The mean of the sum of superior retinal artery (SRA) and inferior retinal artery (IRA) VC and the mean of the sum of superior retinal vein (SRV) and inferior retinal vein (IRV) VC before and after the drop were compared. Results: There was no statistically significant change in the mean sum of SRA and IRA VC and the mean sum of SRV and IRV VC before and after dilatation drops in all three groups. Conclusion: Dilatation drops have no statistically significant effect on retinal artery and vein VC. [ABSTRACT FROM AUTHOR]

The article "What is Occluding Our Understanding of Retinal Vein Occlusion?" published in Ophthalmology & Therapy discusses the rising prevalence of retinal vein occlusion (RVO) and the complexity of its pathogenesis. It emphasizes the need to address unmet needs within the RVO patient journey by leveraging advancements in imaging, biomarkers, and novel treatments. The text highlights gaps in understanding the pathogenesis, risk factors, and treatment strategies for RVO, calling for individualized care and improved diagnostic investigations. The article also discusses recent clinical trials investigating faricimab and the potential of dual inhibition therapy in improving outcomes for patients with RVO. [Extracted from the article]

Purpose: To evaluate the impact of high-risk optic disc (HROD) on central retinal vein occlusion (CRVO) in patients with metabolic disorder(s). Design: Retrospective case-control study. Methods: A case-control study involving CRVO patients with metabolic disorder(s) was performed. PART I. All eligible patients with CRVO were included in CRVO group, and a similar number of patients with metabolic disorder(s) without CRVO were matched by sex, age and blood glucose level in the non-CRVO group. Various parameters were compared between groups. The impact of risk factors associated with CRVO was presented as odds ratios (ORs) and 95% confidence interval (95% CI). PART II. All eyes with CRVO that underwent intravitreal treatment (IVT) with a follow-up duration of ≥1 year were divided into non-HROD and HROD groups, and the differences between the two groups were compared. Results: In PART I, a total of 45 and 63 eyes were enrolled in the CRVO and non-CRVO groups, respectively, with a significant statistical difference in HROD (51.16% vs 26.98%, p = 0.010) between them. In further multivariate regression analysis, HROD was the independent risk factor for CRVO (OR = 5.036, 95% CI 1.847-13.729, p = 0.002). In PART II, demographic, follow-up information, treatment, and prognosis showed no significant statistical difference between the two groups (all p > 0.05).* Conclusion: HROD was likely to be an independent risk factor for CRVO occurrence in patients with metabolic disorder(s), but it did not affect the treatment and prognosis of CRVO eyes with HROD. [ABSTRACT FROM AUTHOR]

Alzheimer's disease is the most prevalent form of dementia. Apart from its traditional clinical diagnostic methods, novel ocular imaging biomarkers have the potential to significantly enhance the diagnosis of Alzheimer's disease. Ophthalmologists might be able to play a crucial role in this multidisciplinary approach, aiding in the early detection and diagnosis of Alzheimer's disease through the use of advanced retinal imaging techniques. This systematic literature review the utilization of optical coherence tomography angiography biomarkers, specifically vessel density and the foveal avascular zone, for the diagnosis of Alzheimer's disease. A comprehensive search was performed across multiple academic journal databases, including 11 relevant studies. The selected studies underwent thorough analysis to assess the potential of these optical coherence tomography angiography biomarkers as diagnostic tools for Alzheimer's disease. The assessment of vessel density and the foveal avascular zone have emerged as a promising avenue for identifying and diagnosing Alzheimer's disease. However, it is imperative to acknowledge that further targeted investigations are warranted to address the inherent limitations of the existing body of literature. These limitations encompass various factors such as modest sample sizes, heterogeneity among study populations, disparities in optical coherence tomography angiography imaging protocols, and inconsistencies in the reported findings. In order to establish the clinical utility and robustness of these biomarkers in Alzheimer's disease diagnosis, future research endeavors should strive to overcome these limitations by implementing larger-scale studies characterized by standardized protocols and comprehensive assessments. [ABSTRACT FROM AUTHOR]

Purpose: In this study, we aimed to evaluate and compare the effects of intravitreal aflibercept (IVA) and intravitreal faricimab (IVF) injections on the blood flow of retinal vessels in the peripapillary region and optic nerve head (ONH) in eyes with diabetic macular edema (DME) using laser speckle flowgraphy (LSFG). Patients and Methods: This study included 20 eyes of 18 patients treated with IVA and 15 eyes of 11 patients treated with IVF for DME. The mean blur rate (MBR) of the ONH and retinal artery and vein of the peripapillary region were measured using LSFG at baseline and 1 month after injection. Central retinal thickness (CRT) and best-corrected visual acuity (BCVA) were measured for all patients. Results: CRT decreased significantly in both IVA-treated (p = 0.0003) and IVF-treated groups (p = 0.0004). Some of the MBR-related parameters of the ONH, such as MBR of all areas (MA), MBR of vascular areas (MV), and MBR of tissue areas (MT), decreased significantly 1 month after IVA and IVF compared to baseline values (MA of IVA, p < 0.0001; MT of IVA, p = 0.0220; MA of IVF, p = 0.0002; MT of IVF, p = 0.0461). MBR of the retinal artery (MBR-A) and vein (MBR-V) also decreased significantly 1 month after IVA and IVF compared with baseline values (MBR-A of IVA, p = 0.0002; MBR-V of IVA, p = 0.0010; MBR-A of IVF, p = 0.0368). No significant difference in ocular perfusion was observed between the IVA-treated and IVF-treated groups. Conclusion: Intravitreal injection led to a reduction in ocular blood flow in both retinal peripapillary vessels and the ONH in both IVA-treated and IVF-treated groups. No significant difference was observed in MBR reduction between the IVA-treated and IVF-treated groups. Our findings warrant further long-term investigations to reveal differences between aflibercept and faricimab. [ABSTRACT FROM AUTHOR]

Background: Carotid artery stenosis (CAS) is one of the most common macrovascular complications of hypertension. The ophthalmic artery springs from the internal carotid artery; however, the effect of CAS on ocular microcirculation has not been quantified in hypertension patients. This study aimed to quantify ocular microcirculation metrics in hypertension with CAS (HCAS) patients and to explore the relationship between micro- and macroangiopathy in hypertension. Methods: All participants (community-based) underwent detailed assessments, including carotid ultrasonography, optical coherence tomography angiography (OCTA), and enhanced depth imaging (EDI)-OCT. CAS was diagnosed using carotid ultrasonography. Retinal microcirculation metrics, including vessel density (VD), skeleton density (SD), fractal dimension (FD), and foveal avascular zone (FAZ), were quantified using OCTA and ImageJ software. Choroidal microcirculation metrics, including subfoveal choroidal thickness (SFCT), luminal area (LA), and choroidal vascularity index (CVI), were quantified using EDI-OCT and ImageJ. Retinal vessel caliber metrics, including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery/vein ratio (AVR), were calculated using revised formulas. The above metrics were compared among the HCAS group, hypertension with no CAS (HNCAS) group, and healthy control group. The mutual effects between ocular metrics and CAS were evaluated using regression analyses. Results: In a comparison of the HCAS vs. HNCAS groups, retinal metrics including VD, SD, FD, and choroidal metrics including CVI and LA were significantly decreased in the HCAS group (all p < 0.05); however, FAZ, SFCT, and retinal vessel caliber metrics including CRAE, CRVE, and AVR were comparable between groups (all p > 0.05). In a comparison of HNCAS and the healthy control group, VD, SD, and CRAE showed that AVR was significantly decreased in the HNCAS group (all p < 0.05); meanwhile, choroidal metrics were comparable between groups (all p > 0.05). Linear regression analyses showed that intimamedia thickness (IMT) (p = 0.01) and peak systolic velocity (PSV) (p = 0.002) were negatively related to retinal VD in hypertension patients. Logistic regression analyses disclosed that older age (p < 0.001), smoking history (p = 0.002), lower VD (p = 0.04), SD (p = 0.02), and CVI (p < 0.001) were related to the presence of CAS in hypertension patients. Conclusion: CAS in hypertension-induced hypoperfusion in retinal and choroidal microcirculation and the decreased retinal VD and choroidal CVI were significantly associated with the presence of CAS in patients with hypertension, suggesting that hypertension macro- and microangiopathy were mutually affected and share the common pathophysiology. Furthermore, OCT could be a useful tool to assess hypertension patient's CAS risk profiles in a non-invasive way. [ABSTRACT FROM AUTHOR]

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Retinal vein cannulation involves puncturing an occluded vessel on the micron scale. Even single millinewton force can cause permanent damage. An ophthalmic robot with a piezo-driven injector is precise enough to perform this delicate procedure, but the uncertain viscoelastic characteristics of the vessel make it difficult to achieve the desired contact force without harming the retina. The paper utilizes a viscoelastic contact model to explain the mechanical characteristics of retinal blood vessels to address this issue. The uncertainty in the viscoelastic properties is considered an internal disturbance of the contact model, and an active disturbance rejection controller is then proposed to precisely control the contact force. The experimental results show that this method can precisely adjust the contact force at the millinewton level even when the viscoelastic parameters vary significantly (up to 403.8%). The root mean square (RMS) and maximum value of steady-state error are 0.32 mN and 0.41 mN. The response time is below 2.51 s with no obvious overshoot. [ABSTRACT FROM AUTHOR]

To develop a highly efficient and fully automated method that measures retinal vessel caliber using digital retinal photographs and evaluate the association between retinal vessel caliber and hypertension. The subjects of this study were from two sources in Beijing, China, a hypertension case-control study from Tongren Hospital (Tongren study) and a community-based atherosclerosis cohort from Peking University First Hospital (Shougang study). Retinal vessel segmentation and arteriovenous classification were achieved simultaneously by a customized deep learning model. Two experienced ophthalmologists evaluated whether retinal vessels were correctly segmented and classified. The ratio of incorrectly segmented and classified retinal vessels was used to measure the accuracy of the model's recognition. Central retinal artery equivalents, central retinal vein equivalents and arteriolar-to-venular diameter ratio were computed to analyze the association between retinal vessel caliber and the risk of hypertension. The association was then compared to that derived from the widely used semi-automated software (Integrative Vessel Analysis). The deep learning model achieved an arterial recognition error rate of 1.26%, a vein recognition error rate of 0.79%, and a total error rate of 1.03%. Central retinal artery equivalents and arteriolar-to-venular diameter ratio measured by both Integrative Vessel Analysis and deep learning methods were inversely associated with the odds of hypertension in both Tongren and Shougang studies. The comparisons of areas under the receiver operating characteristic curves from the proposed deep learning method and Integrative Vessel Analysis were all not significantly different (p >.05). The proposed deep learning method showed a comparable diagnostic value to Integrative Vessel Analysis software. Compared with semi-automatic software, our deep learning model has significant advantage in efficiency and can be applied to population screening and risk evaluation. [ABSTRACT FROM AUTHOR]

Purposes: Retinal vein occlusion (RVO) is a major cause of vision loss. Its pathogenesis is still not completely understood. Our aim was to describe patients with RVO, to precise risk factors responsible to retinal vasculopathy in our population and to assess the prevalence of thrombophilia disorders patients with RVO, compared to population-based group of age- and sex-matched controls. Patients & methods: Our study was retrospective conducted from 1 January 2013, until 30 June 2019, including 57 patients with RVO compared to 105 controls patient's age- and sex-matched free of any visual disorders. Among 57 RVO cases, 26 were men and 31 were women. Results: The mean age was 45.0±14.7 years. Among systemic and ocular risk factors for RVO we found hypertension in 12 patients (31.6%), dyslipidemia in four patients (10.5%), diabetes in four patients (10.5%), and smoking in six patients (16.2%). Three patients (9.7%) had glaucoma and two patients (6.5%) had diabetic retinopathy. Ophthalmology examination found unilateral RVO in 52 patients (91.0%) and bilateral RVO in five patients (11.1%). Retinal angiography showed ischemic signs in seven patients (18.4%). Non-ischemic RVO was retained in 31 cases (81.6%). Macular edema was present in 12 patients (38.7%). Six cases (19.4%) developed neovascular glaucoma and two cases (6.5%) presented reversible blindness. Measures of thrombophilia practiced in 57 patients revealed 13 abnormalities (22.8%): Isolated thrombophilia disorder in 11 patients (71.4%) and combined prothrombotic disorder in two others. Conclusions: Among systemic and ocular risk factors for RVO, we found hypertension in 12 patients (31.6%). Thrombophilia disorders were also common. [ABSTRACT FROM AUTHOR]

Kounis Syndrome (KS) is a clinical entity triggered by allergic or hypersensitivity reactions capable of inducing acute coronary events. Several causes can induce KS, including drugs and insect stings. Here, a rare case of post mortem assessment of fatal KS related to fluorescein retinal angiography has been reported. An 80-year-old man in follow-up for a retinal vein thrombosis underwent a retinal fluoroangiography. Approximately 30 min later, the patient complained of sweating and dizziness, and suddenly lost consciousness due to a cardiac arrest. Despite the immediate cardiopulmonary resuscitation, he died. The autopsy revealed foamy yellowish edema in the respiratory tract and coronary atherosclerosis with eccentric plaques partially obstructing the lumen. The routine histology highlighted lung emphysema and myocyte break-up with foci of contraction band necrosis at the myocardial tissue. Biochemistry showed increased serum tryptase, troponin, and p-BNP. Activated and degranulated (tryptase) mast cells were detected, using immunohistochemistry, in the larynx, lungs, spleen, and heart. Acute myocardial ischemia due to allergic coronary vasospasm related to fluorescein hypersensitivity has been assessed as cause of death. KS-related deaths are considered rare events, and the post mortem assessment of KS quite difficult. The integration of several investigations (gross and microscopic examination, biochemistry, immunohistochemistry) can provide useful findings to support the diagnosis, helping to reduce the unrecognized cases as much as possible. [ABSTRACT FROM AUTHOR]

Central serous chorioretinopathy (CSC) is a leading cause of permanent vision loss, ranking fourth among macular diseases, trailing only age-related macular degeneration, diabetic retinopathy, and retinal vein obstruction. While mounting evidence implicates inflammation as a pivotal factor in the onset and advancement of CSC, the specific pathophysiological process and molecular mechanisms underlying inflammation remain incompletely understood. A complex network of cytokines, chemokines, and adhesion molecules interplay to trigger inflammatory and pathological cascades, highlighting the need for a comprehensive comprehension of the inflammation-related mechanisms behind CSC progression. In this piece, we examine the existing comprehension of CSC’s pathology and pathogenesis. Additionally, we present an overview of the mechanisms underlying the onset and progression of CSC inflammation, followed by a thorough analysis and discussion of the potential of targeted inflammatory intervention for both preventing and treating CSC. [ABSTRACT FROM AUTHOR]

Insufficient blood flow within the retinal vessels is believed to be the root cause of several optical problems, including partial vision loss and blindness. The appearance and growth of veins in retinal images are crucial for identifying ocular contamination. It is therefore a significant task for the research community to explore and segment these retinal blood vessels. For a wide range of purposes, including biometric authentication, computer-assisted laser surgery, automated screening, and the detection of ophthalmic pathologies like diabetic retinopathy (DR), age-related macular degeneration, and hypertensive retinopathy, among others, accurate blood vessel delineation in retinal images is used. Stroke and cardiovascular disease are severe illnesses that are preceded by changes in the properties of retinal blood vessels. There are many alternatives to identifying an infection a person has through their eyes in the broad development of innovation, such as diabetes, hypertension, heart disease, rheumatoid arthritis, etc. Examining retinal vascular features can therefore help to spot these changes and allow a person to respond quickly while the illness is still in its early stages. The use of computer-based automation in this procedure would reduce the costs associated with hiring qualified graders and solve the issue of inconsistency that results from manual grading. Numerous tasks involving retinal analysis require the segmentation of retinal vessels because it facilitates the execution of subsequent measures. As a result, segmentation is crucial to the study of retinal images. In the current study, a successful method for automatically extracting blood vessels from coloured retinal pictures is described. In order to solve the retinal blood vessel segmentation problem, we applied feature extraction methodologies and machine learning (ML) techniques in this research. This method uses pixel-based feature extraction, where each pixel has its own feature vector. Five distinct feature groups are employed for feature extraction: the basic line detector for line strength, the orthogonal line detector, the frangi filter, the average grey level features, and the gabor filter. The four machine learning classifiers—K-Nearest Neighbour (KNN), Support Vector Machine (SVM), Naive Bayes, and Decision Tree—are trained using the training data. A DRIVE dataset is used to test the system; it is a benchmark, standard, widely accepted, and openly accessible to the general public. Blood vessel segmentation from fundus pictures is measured using performance metrics like precision, sensitivity, specificity, area under the curve (AUC), and accuracy as success indicators. With the given method, the maximum accuracy achieved is 0.9623 using KNN, 0.9463 using SVM, 0.9459 using Naive Bayes, and 0.9624 using Decision Tree. The findings of previously published extremely efficient approaches are comparable to the performance of the suggested strategy, which has demonstrated great performance. The recommended method can be used as an alternate automated tool for segmenting retinal blood vessels. [ABSTRACT FROM AUTHOR]

Since coronavirus disease infection-19 (COVID-19) entry to the cells is angiotensin enzyme receptor (ACEII) dependent, extrapulmonary manifestations have been suspected. Ocular manifestations reported in several studies to involve the anterior as well as posterior eye segments. However, the predominance of the anterior eye segment reduced the attention of the scientific community on the posterior eye segment. Our results showed that the incidence of changes in the posterior eye segment is 1/5 of the anterior eye segment. Posterior eye segment manifestations include acute macular neuroretinopathy and paracentral middle maculopathy, central retinal vein/artery occlusion, reactivation of previous uveitis, varicella zoster virus-related acute retinal necrosis in an immunocompromised patient, chorioretinitis, macular hemorrhage, paracentral acute middle maculopathy, retinal detachment, and vitritis with outer retinal abnormalities. The pathogenesis of posterior eye segment manifestations under COVID-19 includes viremia, autoimmune vasculitis, hyperimmune response, coagulopathy, and cytokine storm. A full ophthalmological examination is crucial for patients recovering from COVID-19. The paper provided up-to-date manifestations with potential underlying pathophysiological mechanisms of development, as well as pathogenetic therapy. [ABSTRACT FROM AUTHOR]

Purpose: To compare the results of retinal venous pressure (RVP) measurement performed with contact lens dynamometry (CLD) and with the new IOPstim. Methods: In this cross-sectional study, we included 36 patients with primary open angle glaucoma with a median age (Q25; Q75) of 74 (64; 77) years (m/f = 18/18), baseline intraocular pressure (IOP): 13.9 (12.2; 15.1) mmHg. Median mean defect: − 5.8 (− 11.9; − 2.6) db. Principle of the IOPstim: an empty balloon with a diameter of 8 mm is positioned on the eye, laterally of the limbus. Under observation of the central retinal vein (CRV), the examiner inflates the balloon. As soon as the CRV starts pulsation, the inflation is stopped and the IOP is measured, equaling the RVP at this moment. In the CLD, the pulsation of the CRV is observed with a contact lens. The RVP is calculated from the attachment force applied when pulsation appears. Course of examinations: Three single measurements of RVP in quick succession with both methods. The sequence of the two methods was randomized. The means of the three RVP measurements were compared. Results: Pressures in mmHg. RVP: IOPstim: 19.4 ± 5.4 (mean ± SD), CLD: 20.3 ± 5.9. Range of three single measurements: IOPstim: 2.9 ± 1.5, CLD: 2.2 ± 1.1. The differences were RVPIOPstim − RVPCLD = − 0.94 ± 1.15, and approximately normally distributed. Bland–Altman analysis: only one data point was 0.5 mmHg higher than the upper line of agreement. The confidence interval of this line was 0.65 mmHg. Concordance correlation coefficient according to Lin (CCC): 0.96. Intraclass correlation coefficient: both methods, 0.94. Conclusion: In both methods, the range of the single measurements may be taken as a sign of good reliability, the CCC of 0.96 as a sign of a very good agreement. At the mean, the IOPstim RVP values were 1 mmHg lower than those obtained with the CLD. This difference may be due to the different directions of the prevailing force vectors induced by the instruments. The IOPstim seems applicable in glaucoma diagnostics. [ABSTRACT FROM AUTHOR]

Introduction: The classically defined two retinal microglia layers are distributed in inner and outer plexiform layers. Although there are some reports that retinal microglia are also superficially located around the ganglion cell layer (GCL) in contact with the vitreous, there has been a lack of detailed descriptions and not fully understood yet. Methods: We visualized the microglial layers by using CX3CR1-GFP (C57BL6) transgenic mice with both healthy and disease conditions including NaIO3- induced retinal degeneration models and IRBP-induced auto-immune uveitis models. Result: We found the GCL microglia has two subsets; peripheral (pph) microglia located on the retinal parenchyma and BAM (CNS Border Associated Macrophage) which have a special stretched phenotype only located on the surface of large retinal veins. First, in the pph microglia subset, but not in BAM, Galectin-3 and LYVE1 are focally expressed. However, LYVE1 is specifically expressed in the amoeboid or transition forms, except the typical dendritic morphology in the pph microglia. Second, BAM is tightly attached to the surface of the retinal veins and has similar morphology patterns in both the healthy and disease conditions. CD86+ BAM has a longer process which vertically passes the proximal retinal veins. Our data helps decipher the basic anatomy and pathophysiology of the retinal microglia in the GCL. Discussion: Our data helps decipher the basic anatomy and pathophysiology of the retinal microglia in the GCL. [ABSTRACT FROM AUTHOR]

Microinjection is usually applied to the treatment of some retinal disorders, such as retinal vein cannulation and displaced submacular hemorrhage. Currently, the microinjection procedure is usually performed by using the viscous fluid control of a standard vitrectomy system, which applies a fixed air pressure through foot pedal activation. The injection process with the fixed pressure is uncontrollable and lacks feedback, the high flow rate of the injected drug may cause damage to the fundus tissue. In this paper, a liquid-driven microinjection system with a flow sensor is designed and developed specifically for fundus injection. In addition, a PID sliding mode control (SMC) method is proposed to achieve precise injection in the injection system. The experimental results of fundus simulation injection demonstrate that the microinjection system meets the requirements of fundus injection and reduces the impact of the injection process on the fundus tissue. [ABSTRACT FROM AUTHOR]

The given text is a list of references related to Terson's Syndrome, a condition characterized by bleeding in the eye that occurs as a result of subarachnoid hemorrhage. The references include studies, case reports, and reviews that discuss various aspects of Terson's Syndrome, such as its incidence, clinical features, diagnostic methods, and treatment options. The references provide valuable information for researchers and healthcare professionals interested in understanding and managing this condition. [Extracted from the article]

Aim of the study: To study the peculiarities of retinal changes’ structure and frequency according to fundoscopy data in patients with different clinical course of COVID-19. Material and methods: This was prospective, uncontrolled crosssectional study. A total of 117 patients (234 eyes) with varying severity of COVID-19 clinical course were divided into groups: 1) an extremely severe course; 2) a severe course; 3) moderate severity with decompensated accompanying pathology; 4) moderate severity with compensated concomitant pathology. Registration of patients’ eye fundus with the portable fundus camera Pictor Plus Fundus Camera and VistaView (Volk Optical). Results: Cotton wool spots, narrowed retinal vessels, central retinal vein occlusion (CRVO) (8.8%), petechial and intraretinal hemorrhages (23.5%), tortuosity and dilatation of retinal venules (11.8%), prethrombosis of the central retinal vein (CRV) (a state determined by venous blood stasis, characterized by dilated appearance of the eye fundus veins, their dark color, curved structure, optic nerve edema) (2.9%) and vitreous hemorrhage (5.9%) were found in 1st group patients; in 29.4% of cases there were no retinal changes. Retinal changes were absent in 59.3% in 4th group patients and in 86.7% in 3rd group patients; no clinically significant retinal changes were detected in these patients. Conclusions: Retinal changes’ structure and frequency in patients with COVID-19 correlate with the severity of its clinical course. Within 1st group patients cotton wool spots, narrowed retinal vessels, petechial and intraretinal hemorrhages, thrombosis/prethrombosis of CRV, tortuosity and dilatation of retinal venules, and vitreous hemorrhage are diagnosed, which is significantly more common than in patients of 3rd and 4th groups (p < 0.05). A trend of decreasing risk of clinically significant retinal changes (thrombosis/ prethrombosis of CRV) and vitreous hemorrhage with decreasing severity of the disease was observed. [ABSTRACT FROM AUTHOR]

We conducted a scoping review of studies examining ambient air pollution as a risk factor for chronic eye disease influencing the lens, retina, and intraocular pressure in adults. Terms related to air pollution and eye disease outcomes were used to search for publications on Embase, Web of Science Core Collection, Global Health, PubMed, and the Cochrane Central Register of Controlled Trials from January 1, 2010, through April 11, 2022. We identified 27 articles, focusing on the following non-mutually exclusive outcomes: cataract (n = 9), presbyopia (n = 1), retinal vein occlusion or central retinal arteriolar and venular equivalents (n = 5), intraocular pressure (IOP) (n = 3), glaucoma (n = 5), age-related macular degeneration (AMD) (n = 5), diabetic retinopathy (n = 2), and measures of retinal morphology (n = 3). Study designs included cross-sectional (n = 16), case–control (n = 4), and longitudinal (n = 7). Air pollutants were measured in 50% and 95% of the studies on lens and retina or IOP, respectively, and these exposures were assigned to geographic locations. Most research was conducted in global regions with high exposure to air pollution. Consistent associations suggested a possibly increased risk of cataract and retina-associated chronic eye disease with increasing exposure to particulate matter (PM2.5-PM10), NO2, NOx, and SO2. Associations with O3 were less consistent. Accumulating research suggests air pollution may be a modifiable risk factor for chronic eye diseases of the lens and retina. The number of studies on each specific lens- or retina-related outcome is limited. Guidelines regarding the role of air pollution in chronic eye disease do not exist. [ABSTRACT FROM AUTHOR]

Background: To review cases of branch retinal vein occlusion (BRVO) secondary to rhegmatogenous retinal detachment (RRD) and its surgical management and presume their mechanism. Methods: Medical records of patients who underwent surgery for RRD between 2015 and 2019 at a single tertiary care center were retrospectively reviewed. New BRVO secondary to RRD or its surgical procedure was diagnosed based on the fundus examination and its clinical course. Results: A total of 734 RRD surgeries were performed for five years, and six cases of new BRVOs were noticed in the first year after surgery (incidence was 0.68%: six cases of BRVO / 734 cases of surgical RRD); five cases occurred after vitrectomy, and one occurred after scleral buckling. In three cases, retinal veins were presumed to already be partially occluded related due to a kink of the retinal vein seen before surgery. In the other three cases, the retinal veins were presumed to have incurred damage during vitrectomy. Conclusion: In the present cohort, RRD or its related procedures caused BRVO within a year of surgery at an incidence of 0.68%. The proposed mechanisms are kinks of the retinal vein on the detached retina and damage to the retinal vein during vitrectomy. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to assess the effect of bariatric surgery on retinal microvascular calibre, peripheral microvascular function, peripheral pressure waveforms, and the general cardiovascular disease (CVD) risk in obese individuals after undergoing Roux-en-Y gastric bypass (RYGB) surgery. Methods: A total of 29 obese participants were included in the study. All of the measurements were conducted at two time points: before and one year following the bariatric surgery procedure. General anthropometric data, as well as blood markers for glucose, cholesterol, and triglycerides were assessed in all individuals. In all participants, the Framingham risk score (FRS), and retinal vessel calibre measurements, using a Zeiss fundus camera and VesselMap software (ImedosSystems, Jena, Germany), were performed. Systemic arterial stiffness was measured by pulse wave analysis (PWA), and peripheral microvascular reactivity by way of digital thermal monitoring (DTM) in all participants. Results: As expected, various general anthropometric parameters, including body mass index (BMI), waist circumference and neck circumference, were significantly decreased post-surgery comparing to baseline in all individuals (all p < 0.001). In addition, their general CVD risk, as measured using FRS, was significantly improved (p < 0.001). At the retinal vascular level, central retinal artery equivalent (CRAE) as well as, central retinal vein equivalent (CRVE) had increased after surgery comparing to the baseline values (p = 0.003 and p = 0.007, respectively). In addition, both systemic arterial stiffness and peripheral microvascular reactivity had improved in all participants (p < 0.001 and p = 0.008 respectively). Conclusions: Our findings suggest that bariatric surgery has a positive effect on the overall vascular health, as well as on the general CVD risk of the obese patients undergoing this procedure. [ABSTRACT FROM AUTHOR]

Background: High cholesterol impacts blood vesssels in every part of the body. Lipemia retinalis is a rare retinal presentation of severe hypertriglyceridemia (usually greater than 2000 mg/dl), resulting in a creamy-white discoloration of retinal blood vessels. The following case presents a pediatric case of lipemia retinalis. Case Report: A 15-year-old Hispanic female presented for an annual diabetic eye exam. She reported that her vision had been blurry OU since she lost her glasses. Her medical history included type 2 DM, diagnosed 1 year prior. Her last blood glucose was 208 mg/dL, and she did not know her HbA1c. Her medications included metformin and insulin. DFE revealed creamy-white colored arteries and veins in both eyes and a salmon-colored fundus, but no evidence of diabetic retinopathy. OCT showed increased signal in the blood vessel lumens. Her lab work showed total cholesterol of 1328 mg/dL and triglycerides of 7337 mg/ dL. The PCP started the patient on a low-fat diet, antitryglyceride, and anticholesteral medication. Conclusion: Visual sequelae associated with lipemia retinalis is rare, as most patients are visually asymptomatic. There is no treatment for the lipemia retinalis itself, other than managing the underlying systemic metabolic pathologies. Coordination with the primary care physician is required. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate perivascular reflectivity in patients with branched retinal vascular obstruction (BRVO) using en-face optical coherence tomography (OCT). The study retrospectively analyzed 45 patients with recurrent BRVO, 30 with indolent BRVO, and 45 age- and sex-matched controls. Using a 3.0 × 3.0-mm deep capillary plexus slab on macular scans, OCT angiography (OCTA) and structural en-face OCT scans were divided into four quadrants. Obstructive quadrants of OCTA scans were binarized using a threshold value of mean + 2 standard deviation. The selected area of high signal strength (HSS) was applied to the structural en-face OCT scans, and the corrected mean perivascular reflectivity was calculated as the mean reflectivity on the HSS area/overall en-face OCT mean reflectivity. The same procedure was performed in the quadrants of the matched controls. Regression analysis was conducted on several factors possibly associated with corrected perivascular reflectivity. The perivascular reflectivity in the obstructive BRVO quadrant was significantly higher than in the indolent BRVO and control quadrants (P = 0.009, P = 0.003). Both univariate and multivariate regression analyses showed a significant correlation between the average number of intravitreal injections (anti-vascular endothelial growth factor or dexamethasone implant) per year and refractive errors and image binarization threshold and perivascular reflectivity (P = 0.011, 0.013, < 0.001/univariate; 0.007, 0.041, 0.005/multivariate, respectively). En-face OCT scans of the deep capillary plexus slab revealed higher perivascular reflectivity in recurrent BRVO eyes than in indolent BRVO and control eyes. The results also indicate a remarkable correlation between perivascular reflectivity and the average number of intravitreal injections, suggesting a link to recurrence rates. [ABSTRACT FROM AUTHOR]

Older individuals experience cardiovascular dysfunction during extended bedridden hospital or care home stays. Bed rest is also used as a model to simulate accelerated vascular deconditioning occurring during spaceflight. This study investigates changes in retinal microcirculation during a ten-day bed rest protocol. Ten healthy young males (22.9 ± 4.7 years; body mass index: 23.6 ± 2.5 kg·m–2) participated in a strictly controlled repeated-measures bed rest study lasting ten days. High-resolution images were obtained using a hand-held fundus camera at baseline, daily during the 10 days of bed rest, and 1 day after re-ambulation. Retinal vessel analysis was performed using a semi-automated software system to obtain metrics for retinal arteriolar and venular diameters, central retinal artery equivalent and central retinal vein equivalent, respectively. Data analysis employed a mixed linear model. At the end of the bed rest period, a significant decrease in retinal venular diameter was observed, indicated by a significantly lower central retinal vein equivalent (from 226.1 µm, CI 8.90, to 211.4 µm, CI 8.28, p =.026), while no significant changes in central retinal artery equivalent were noted. Prolonged bed rest confinement resulted in a significant (up to 6.5%) reduction in retinal venular diameter. These findings suggest that the changes in retinal venular diameter during bedrest may be attributed to plasma volume losses and reflect overall (cardio)-vascular deconditioning. [ABSTRACT FROM AUTHOR]

Retinal imaging is a non-invasive technique used to scan the back of the eye, enabling the extraction of potential biomarkers like the artery and vein ratio (AVR). This ratio is known for its association with various diseases, such as hypertensive retinopathy (HR) or diabetic retinopathy, and is crucial in assessing retinal health. HR refers to the morphological changes in retinal vessels caused by persistent high blood pressure. Timely identification of these alterations is crucial for preventing blindness and reducing the risk of stroke-related fatalities. The main objective of this paper is to propose a new method for assessing one of the morphological changes in the fundus through morphometric analysis of retinal images. The proposed method in this paper introduces a novel approach called the arteriovenous length ratio (AVLR), which has not been utilized in previous studies. Unlike commonly used measures such as the arteriovenous width ratio or tortuosity, AVLR focuses on assessing the relative length of arteries and veins in the retinal vasculature. The initial step involves segmenting the retinal blood vessels and distinguishing between arteries and veins; AVLR is calculated based on artery and vein caliber measurements for both eyes. Nine equations are used, and the length of both arteries and veins is measured in the region of interest (ROI) covering the optic disc for each eye. Using the AV-Classification dataset, the efficiency of the iterative AVLR assessment is evalutaed. The results show that the proposed approach performs better than the existing methods. By introducing AVLR as a diagnostic feature, this paper contributes to advancing retinal imaging analysis. It provides a valuable tool for the timely diagnosis of HR and other eye-related conditions and represents a novel diagnostic-feature-based method that can be integrated to serve as a clinical decision support system. [ABSTRACT FROM AUTHOR]

Diabetes causes DR. Diabetes duration influences retinopathy development. The retinal vein weakening may have no side effects or a little eyesight impairment at initially. Blindness may occur. DR intervention and treatment need early clinical indications. Thus, frequent eye examinations must guide patients to a doctor for a full eye inspection and therapy to avoid irreversible vision loss. This work develops a machine learning-based optical image-based data classification method for diabetic retinopathy identification. OCT analyses the retinal picture and the ensemble pulse coupled filtering and green histogram channel equalization-based adaptive filtering segment this picture for blood vessel characterization. CenterResnet-50 classifies images for color fundus detection. Classification accuracy, sensitivity, specificity, AUC, and ROC curves were examined for various optical retina pictures. The proposed method has 98% classification accuracy, 67% sensitivity, 73% specificity, and 63% AUC. [ABSTRACT FROM AUTHOR]

A rarely described condition known as branch retinal artery occlusion (BRAO) with concurrent obstruction of the central retinal vein (CRVO) is characterized by diffuse retinal hemorrhages, dilated and tortuous retinal veins, macular and disc edema, cotton wool spots, and a generalized delay in arteriovenous transit on fluorescein angiography, together with a retinal whitening in the area of the affected retinal arterial branch. Although BRAO and CRVO may share underlying systemic risk factors, the pathogenesis of combined BRAO + CRVO is still unknown. We present a BRAO + CRVO case report concerning a 63-year-old white male who came to our observation complaining of sudden vision loss in his right eye. An increased risk for thrombotic event was revealed in this case, and the patient improved only with systemic anticoagulant therapy and in the absence of ocular therapy. We also explain all the clinical findings that are detectable using different diagnostic devices and analyze the scientific literature for other, similar clinical cases. [ABSTRACT FROM AUTHOR]

The tortuosity of retinal blood vessels is an important phenomenon, and it can act as a biomarker in the diagnosis of several eye diseases. The study of abnormalities in the tortuosity of retinal arteries and veins provides ophthalmologists with important information for disease diagnosis. Our study aims to compare the tortuosity relation between retinal arteries and veins by quantifying the vessels' tortuosity in the retina using 14 tortuosity measures applied to the AV-classification retinal dataset. Two feature sets are created, one for arteries and the other for veins. The comparison between the tortuosity of arteries and veins is based on a two-sample T-test statistical method, a regression analysis between the quantified tortuosity features, principal component analysis at the dataset level, and the introduction of the arteriovenous length ratios concept to compare the variations in these new ratios to see the tortuosity behavior in each image. The methods' results have shown that the tortuosity of retinal arteries and veins is similar. The result of the two-sample T-test supports the research hypothesis, as the P-value obtained was greater than 0.05. Furthermore, the regression analysis between arteries and veins features showed a high correlation ( r 2 = 89.39% and 89.11%) for arteries and veins, respectively. The study concludes that the retinal vessel type has no statistical significance in the tortuosity calculation results. [ABSTRACT FROM AUTHOR]

We present the case of a pregnant young woman with symptomatic diffuse choroidal hemangioma (CH), diagnosed with Sturge-Weber syndrome (SWS). Three months postpartum, there was full spontaneous resolution of the subretinal fluid and improvement in the visual acuity (VA). A 29-year-old, 31-week pregnant female with a coagulation disorder and enoxaparin (clexane) treatment, complained of a left visual disturbance of 2 weeks duration. On examination, the right eye was normal; left eye VA was 6/12 (20/40) with a left eyelid port-wine stain and on funduscopic examination there was a serous retinal detachment. On ultrasound, there was diffuse thickening of the choroid with a focus superior and nasal to the disc with active vascularization - a diagnosis of diffuse CH was made. Magnetic resonance imaging (MRI) and MR venography studies of the brain and orbit revealed engorged orbital vasculature, and the diagnosis of SWS was made. Three months after Cesarean section with birth of a healthy baby boy, VA returned to 6/9 with full resorption of subretinal fluid. On fundoscopic exam, there were no retinal or vein occlutions but there were tortuous blood vessels with A-V crossing. This is a rare case of newly diagnosed SWS with symptomatic diffuse CH in pregnancy. Postpartum, there was full resolution of the subretinal fluid. A watchful waiting approach can be considered in such cases. [ABSTRACT FROM AUTHOR]

Purpose: To compare the efficacy of intravitreal ziv-aflibercept (IVZ) and bevacizumab (IVB) injections for the treatment of macular edema secondary to central retinal vein occlusion.Methods: Participants were randomly assigned 1:1 to receive 3 monthly IVZ (1.25 mg/0.05 mL) or IVB (1.25 mg/0.05 mL) followed by the pro-re-nata protocol for persistent or recurrent macular edema. The primary outcomes were best-corrected visual acuity and central subfield thickness. An interim analysis was planned when half of the participants completed the follow-up.Results: Twenty-four participants were recruited. At 6 months, mean best-corrected visual acuity in the IVB and IVZ groups improved from 1.23 ± 0.64 to 0.76 ± 0.56 logMAR (p = 0.003) and from 1.13 ± 0.59 to 0.53 ± 0.26 logMAR (p = 0.003), respectively. The percentage of visual improvement and reduction in central subfield thickness in the IVZ group were insignificantly better than those in the IVB group (44.41 ± 26.72 vs 39.64 ± 24.22%; p = 0.65) and (51.94 ± 20.35 vs 45.78 ± 24.71%; p = 0.51), respectively. Although the mean number of injections was lower in the IVZ group (4.55 ± 1.29 vs 4.82 ± 1.33), the difference was not statistically significant (p = 0.68). No ocular or systemic adverse events were observed.Conclusion: The interim analysis demonstrated that the visual and anatomical results of IVZ were insignificantly better than those of IVB at 6 months of follow-up. The results also showed that IVZ was non-inferior to IVB for anatomical improvement but inconclusive for visual improvement.Clinical Trial Registration: (identifier: TCTR20191205008). [ABSTRACT FROM AUTHOR]

This article presents a study that explores the connection between a particular gene variant and the risk of age-related macular degeneration (AMD). The study involved 121 AMD patients and 108 healthy individuals, and genetic testing was conducted using PCR. The findings revealed a significant correlation between the Del/Del genotype and susceptibility to AMD. The study suggests that this gene variant may contribute to the risk of AMD in the general population. Additionally, the study confirms previous research indicating that smoking and outdoor work are risk factors for AMD. However, further investigation is necessary to validate these findings in larger groups of people. [Extracted from the article]

This document contains summaries of five different articles related to pediatric radiology. The first article discusses tracheobronchial abnormalities in children with congenital heart disease, finding that these abnormalities are commonly associated with the condition. The second article explores a new diagnostic algorithm using lung ultrasound and procalcitonin levels to assess the need for antibiotics in children with suspected bacterial pneumonia, finding that this approach can avoid radiation exposure and unnecessary treatment. The third article examines ocular blood flow in preterm neonates and suggests that ultrafast plane-wave Doppler ultrasound can complement ophthalmoscopy in identifying neonates at risk for retinopathy of prematurity. The fourth article evaluates the predictive value of bronchoscopy combined with CT score in identifying children with refractory Mycoplasma pneumoniae pneumonia, finding that this combined score is more accurate than either method alone. The fifth article compares the incidence of lower respiratory tract infections in children with congenital lung abnormalities who underwent surgery versus those who were managed expectantly, finding no significant difference between the two groups but a decrease in infections after surgical resection. [Extracted from the article]

This article discusses a rare case of a 12-year-old boy with unilateral retinitis pigmentosa (RP) in one eye and macular coloboma and pigmented paravenous chorioretinal atrophy (PPCRA) in the other eye. RP is a hereditary disorder characterized by the progressive loss of photoreceptor and retinal pigment epithelium function. Macular coloboma is a stationary inherited dysplasia of the chorioretinal tissue, and PPCRA is a rare disorder characterized by retinal pigment epithelial atrophy and pigment clumping. The article emphasizes the importance of performing investigations, such as electroretinogram, to differentiate between unilateral and asymmetric RP. [Extracted from the article]

Background: The purpose of this study is to describe a patient who experienced simultaneous central retinal vein and cilioretinal artery occlusions, as well as perifoveal hemorrhage in the Henle fiber. Case presentation: A 67-year-old Iranian woman presented with a 3-day history of reduced vision in her left eye. Venous tortuosity and retinal hemorrhage were observed in the retina, together with whitened regions around the fovea, consistent with the diagnosis of central retinal vein occlusion in conjunction with cilioretinal artery occlusion. In structural and en face optical coherence tomography, star-shaped hemorrhages were observed around the fovea, which looked hyperreflective in the Henle fiber layer. Conclusions: We present a case of central retinal vein occlusion exacerbated by cilioretinal occlusion and hemorrhage in the Henle fiber layer. The hemorrhage is most likely the result of increased intraluminal pressure in the deep capillary plexus. [ABSTRACT FROM AUTHOR]

Introduction: Cystoid macular edema (CME) is the most common cause of central vision loss in eyes with branch retinal vein occlusion (BRVO eyes). In recent literature, choroidal vascularity index (CVI) has been proposed to be an enhanced depth imaging optical coherence tomography (EDI-OCT) metric that may help characterize choroidal vascular changes in the setting of retinal ischemia, and potentially prognose visual outcomes and treatment patterns for patients with BRVO-related CME. This study sought to further characterize choroidal vascular changes in BRVO by comparing the CVI, subfoveal choroidal thickness (SFCT), and central subfield thickness (CST) in BRVO eyes with CME compared to unaffected fellow eyes. Methods: This was a retrospective cohort study. Subjects included treatment-naïve BRVO eyes with CME diagnosed within 3 months of onset of symptoms and unaffected fellow eyes. EDI-OCT images were collected at baseline and at the 12-month follow-up visit. CVI, SFCT, and CST were measured. Demographics, treatment patterns, and best-corrected visual acuity (VA) were abstracted. Median CVI, SFCT, CST, and VA were compared between the two cohorts. Longitudinal relationships between these variables were analyzed. Results: A total of 52 treatment-naïve eyes with BRVO and CME and 48 unaffected fellow eyes were identified. Baseline CVI was lower in eyes with BRVO than in fellow eyes (64.7% vs. 66.4%, P = 0.003). At 12 months, there was no difference in CVI between BRVO eyes and fellow eyes (65.7% vs 65.8%, P = 0.536). In BRVO eyes, there was a strong correlation between reduced CST and improved VA over the 12-month study period (r = 0.671, P < 0.001). Conclusion: There are differences in CVI in treatment-naïve BRVO eyes with CME at presentation compared to fellow eyes, but these differences resolve over time. Anatomic changes in macular thickness in BRVO eyes with CME may be correlated with VA outcomes. Plain Language Summary: Our study evaluated a novel ocular optical coherence tomography imaging metric, the choroidal vascularity index, in eyes that developed cystoid macular edema, a condition which can significantly impair acuity of central vision, after being diagnosed with branch retinal vein occlusion. In each patient, we compared the choroidal vascularity index in eyes that developed treatment-naïve, newly diagnosed branch retinal vein occlusion with cystoid macular edema to the non-diseased fellow eye. We made comparisons at the time of diagnosis (baseline) and at the 12-month follow up, and analyzed changes over time. We found that at the baseline visit, branch retinal vein occlusion eyes with cystoid macular edema had a significantly lower choroidal vascularity index than their unaffected fellow eyes, but that the differences between eyes resolved by the 12-month follow-up visit. Our findings suggest that choroidal vascularity may be compromised in the acute phase of branch retinal vein occlusion, but that this phenomenon resolves over time. Future research should further evaluate whether imaging characteristics of choroidal vascularity may be associated with changes in anatomic and visual outcomes in retinal diseases. [ABSTRACT FROM AUTHOR]

Retinal vein segmentation is a crucial task that helps in the early detection of health problems, making it an essential area of research. With recent advancements in artificial intelligence, we can now develop highly reliable and efficient models for this task. CNN has been the traditional choice for image analysis tasks. However, the emergence of visual transformers with their unique attention mechanism has proved to be a game-changer. However, visual transformers require a large amount of data and computational power, making them unsuitable for tasks with limited data and resources. To deal with this constraint, we adapted the attention module of visual transformers and integrated it into a CNN-based UNET network, achieving superior performance compared to other models. The model achieved a 0.89 recall, 0.98 AUC, 0.97 accuracy, and 0.97 sensitivity on various datasets, including HRF, Drive, LES-AV, CHASE-DB1, Aria-A, Aria-D, Aria-C, IOSTAR, STARE and DRGAHIS. Moreover, the model can recognize blood vessels accurately, regardless of camera type or the original image resolution, ensuring that it generalizes well. This breakthrough in retinal vein segmentation could improve the early diagnosis of several health conditions. [ABSTRACT FROM AUTHOR]

Purpose: To establish an early clinical diagnosis model based on the retinal vascular features associated with POI, supplying a non-invasive way for accurately and early predicted the risk of POI. Methods: A total of 78 women with spontaneous POI and 48 healthy women were recruited from the Affiliated Shenzhen Maternity & Child Healthcare Hospital in the study. Retinal characteristics were analyzed using an automated retinal image analysis system. Binary logistic regression was used to identify POI cases and develop predictive models. Results: Compared to the normal group, the POI group had larger central retinal artery equivalent (CRAE) (P = 0.006), central retinal vein equivalent (CRVE) (P = 0.001), index of venules asymmetry (Vasym) (P = 0.000); larger bifurcation angles of arterioles (Aangle) (P = 0.001), bifurcation coefficient of venule (BCV) (P = 0.001) and more obvious arteriovenous nipping (Nipping) (P = 0.005), but lower arteriole-to-venule ratio (AVR) (P = 0.012). In the POI group, the odds ratio (OR) of Vasym was 6.72e-32 (95% C.I. 4.62e-49–9.79e-15, P = 0.000), the OR of BCV was 5.66e-20 (95% C.I. 1.93e-34–.0000, P = 5.66e-20) and the OR of Nipping was 6.65e-06 (95% C.I. 6.33e-10–.0698, P = 0.012). Moreover, the area under the ROC curve for the binary logistic regression with retinal characteristics was 0.8582, and the fitting degree of regression models was 60.48% (Prob > chi-square = 0.6048). Conclusion: This study demonstrated that retinal image analysis can provide useful information for POI identification and certain characteristics may help with early clinical diagnosis of POI. [ABSTRACT FROM AUTHOR]